Highly specific and sensitive detection of aflatoxin B1 in food based on upconversion nanoparticles-black phosphorus nanosheets aptasensor

Aflatoxin B1 (AFB1) remaining in foodstuff has strong carcinogenicity to humans. Herein, a novel upconversion nanoparticles (UCNPs) aptasensor for detecting AFB1 was constructed based on fluorescence resonance energy transfer, where black phosphorus nanosheets (BPNSs) were applied as acceptors because of the excellent ability to quench visible light emited by UCNPs. In the presence of AFB1, aptamers were preferentially bound to AFB1, resulting in the release of UCNPs from the BPNSs surface and fluorescence of the aptasensors was recovered. Under the optimum conditions, a linear regression range from 0.2 to 500 ng/mL was obtained for the specific detection of AFB1, with a limit of detection of 0.028 ng/mL. In addition, the precision and accuracy of the developed aptasensor showed no significant differences compared with HPLC method in spiked peanut oil and wheat samples detection. It is comfirmed that the developed aptasensor exhibited promising application for AFB1 detection in real food samples.